Accelerated Creep Testing of Inconel 718 Using the Stepped Isostress Method (SSM)

2021 ◽  
Vol 11 (2) ◽  
pp. 20200174
Author(s):  
Calvin M. Stewart ◽  
Md Abir Hossain ◽  
Jacob Pellicotte ◽  
Robert Mach ◽  
David Alexander ◽  
...  
Keyword(s):  
Inconel 718 ◽  
Creep Testing ◽  
Accelerated Creep

scholarly journals Accelerated Creep Test (ACT) Qualification of Creep-Resistance Using the WCS Constitutive Model and Stepped Isostress Method (SSM)

2021 ◽  
Author(s):  
Jaime Cano ◽  
Calvin M. Stewart
Keyword(s):  
Constitutive Model ◽  
Creep Deformation ◽  
Inconel 718 ◽  
Creep Resistance ◽  
Rapid Development ◽  
Superposition Principle ◽  
Continuous Process ◽  
Stress Rupture ◽  
Creep Testing ◽  
Accelerated Creep

Abstract In this study, a qualification of accelerated creep-resistance of Inconel 718 is assessed using the novel Wilshire-Cano-Stewart (WCS) model and the stepped isostress method (SSM) and predictions are made to conventional creep data. Conventional creep testing (CCT) is a long-term continuous process, in fact, the ASME B&PV III requires that 10,000+ hours of experiments must be conducted to each heat for materials employed in boilers and/or pressure vessel components. This process is costly and not feasible for rapid development of new materials. As an alternative, accelerated creep testing techniques have been developed to reduce the time needed to characterize the creep resistance of materials. Most techniques are based upon the time-temperature-stress superposition principle (TTSSP) that predicts minimum-creep-strain-rate (MCSR) and stress-rupture behaviors but lack the ability to predict creep deformation and consider deformation mechanisms that occur for experiments of longer duration. The stepped isostress method (SSM) has been developed which enables the prediction of creep deformation response as well as reduce the time needed for qualification of materials. The SSM approach has been successful for polymer, polymeric composites, and recently has been introduced for metals. In this study, the WCS constitutive model, calibrated to SSM test data, qualifies the creep resistance of Inconel 718 at 750°C and predictions are compared to CCT data. The SSM data is calibrated into the model and the WCS model generates realistic predictions of stress-rupture, MSCR, damage, and creep deformation.

scholarly journals Accelerated Creep Test (ACT) Qualification of Creep-Resistance Using the WCS Constitutive Model and Stepped Isostress Method (SSM)

2021 ◽  
Author(s):  
Jaime A. Cano ◽  
Calvin M. Stewart
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Creep Strain ◽  
Creep Deformation ◽  
Inconel 718 ◽  
Creep Resistance ◽  
Stress Rupture ◽  
Creep Testing ◽  
Accelerated Creep

Abstract In this study, a qualification of accelerated creep-resistance of Inconel 718 is assessed using the novel Wilshire-Cano-Stewart (WCS) model and the stepped isostress method (SSM) and predictions are made to conventional creep data. Conventional creep testing (CCT) is a long-term continuous process, in fact, the ASME B&PV III requires that 10,000+ hours of experiments must be conducted to each heat for materials employed in boilers and/or pressure vessel components. This process is costly and not feasible for rapid development of new materials. As an alternative, accelerated creep testing techniques have been developed to reduce the time needed to characterize the creep resistance of materials. Most techniques are based upon the time-temperature-stress superposition principle (TTSSP) that predicts minimum-creep-strain-rate (MCSR) and stress-rupture behaviors but lack the ability to predict creep deformation and consider deformation mechanisms that occur for experiments of longer duration. The stepped isostress method (SSM) has been developed which enables the prediction of creep deformation response as well as reduce the time needed for qualification of materials. The SSM approach has been successful for polymer, polymeric composites, and recently has been introduced for metals. In this study, the WCS constitutive model, calibrated to SSM test data, qualifies the creep resistance of Inconel 718 at 750°C and predictions are compared to CCT data. The WCS model has proven to make long-term predictions for stress-rupture, minimum-creep-strain-rate (MCSR), creep deformation, and damage in metallic materials. The SSM varies stress levels after time interval adding damage to the material, which can be tracked by the WCS model. The SSM data is calibrated into the model and the WCS model generates realistic predictions of stress-rupture, MSCR, damage, and creep deformation. The calibrated material constants are used to generate predictions of stress-rupture and are post-audit validated using the National Institute of Material Science (NIMS) database. Similarly, the MCSR predictions are compared from previous studies. Finally the creep deformation predictions are compared with real data and is determined that the results are well in between the expected boundaries. Material characterization and mechanical properties can be determined at a faster rate and with a more cost-effective method. This is beneficial for multiple applications such as in additive manufacturing, composites, spacecraft, and Industrial Gas Turbines (IGT).

scholarly journals Effect of Heat Treatment on Properties of INCONEL 617 Investigated in Accelerated Creep Testing

2017 ◽  
Vol 21 (5) ◽  
pp. 273-283
Author(s):  
Noppakorn Phuraya ◽  
Isaratat Phung-on ◽  
Jongkol Srithorn
Keyword(s):  
Heat Treatment ◽  
Creep Testing ◽  
Accelerated Creep ◽  
Inconel 617

scholarly journals Stepwise loading-unloading creep testing of fly ash concrete and its constitutive model

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1539-1545
Author(s):  
Bing Li ◽  
Lian-Ying Zhang ◽  
Yan Li ◽  
Hui-Guang Yin ◽  
Rui-Xue Liu
Keyword(s):  
Fly Ash ◽  
Time Course ◽  
Constitutive Relations ◽  
Creep Testing ◽  
Model Parameters ◽  
Creep Properties ◽  
Fly Ash Concrete ◽  
Accelerated Creep ◽  
Linear Viscoelastic ◽  
Stepwise Loading

Stepwise loading-unloading creep testing of concrete with fly ash content of 35%, and 50% was conducted. The time course curve of stepwise creep in fly ash concrete was obtained. Analyses have revealed that it had decelerated creep, constant velocity, and accelerated creep properties. Based on rheological theory, a non-linear viscoelastic-plastic rheological model (MSSB-NVPB) was constructed, and its constitutive relations and creep equations were obtained. Combined with experimental data, the model parameters were determined. The results showed that this model can characterize the creep properties of the fly ash concrete fairly well.

Development of an Accelerated Creep Testing Procedure for Geosynthetics—Part I: Testing

1997 ◽  
Vol 20 (4) ◽  
pp. 414 ◽  
Author(s):  
RC Chaney ◽  
KR Demars ◽  
K Farrag ◽  
H Shirazi
Keyword(s):  
Testing Procedure ◽  
Creep Testing ◽  
Accelerated Creep
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